Hat Size Calculator & Chart: Never Guess Your Size Again (2026)
Finding your hat size is a pain.
Between US, UK, and European sizing, it’s easy to get confused. And if your measurement is off by even a fraction? You’re stuck with a hat that’s too tight or constantly slides down.
This hat size calculator fixes that.
Just enter your measurement in inches or cm below. You’ll get your exact US, UK, and Euro hat size in seconds.
Hat Size Calculator
Hat Size Conversion Chart (US, UK, & Metric)
Most hat brands use one of three systems.
US sizes are standard for fitted caps. UK sizes are slightly different and usually run 1/8 smaller. If you want the most accurate fit, stick to the Metric (CM) measurement.
Use this table to find your exact match.
| Head Size (In) | Head Size (CM) | US Hat Size | UK Hat Size | Standard Size |
|---|---|---|---|---|
| 20 1/2" | 52 | 6 1/2 | 6 1/8 | XS |
| 20 7/8" | 53 | 6 5/8 | 6 1/4 | XS |
| 21 1/4" | 54 | 6 3/4 | 6 3/8 | S |
| 21 5/8" | 55 | 6 7/8 | 6 1/2 | S |
| 22" | 56 | 7 | 6 5/8 | M |
| 22 3/8" | 57 | 7 1/8 | 6 3/4 | M |
| 22 3/4" | 58 | 7 1/4 | 7 | L |
| 23 1/4" | 59 | 7 3/8 | 7 1/8 | L |
| 23 5/8" | 60 | 7 1/2 | 7 4/4 | XL |
| 24" | 61 | 7 5/8 | 7 3/8 | XL |
| 24 3/8" | 62 | 7 3/4 | 7 1/2 | XXL |
| 24 3/4" | 63 | 7 7/8 | 7 5/8 | XXL |
| 25 1/4" | 64 | 8 | 7 3/4 | XXXL |
| 25 5/8" | 65 | 8 1/8 | 7 7/8 | XXXL |
| 26" | 66 | 8 1/4 | 8 | XXXL |
Heads up: US and UK sizes look almost identical, but they aren't. A UK size is usually one notch smaller than the US version. If you're buying a British brand, always double-check the CM measurement to be safe.
What if you're between two sizes?
This is where most people get stuck. This is especially true if you measure right at 22.5 inches.
Our advice is simple. Always go with the larger size.
It is much easier to fix a hat that is a little loose. You can just use a hat reducer or a bit of foam tape. But a tight hat is a different story. It will give you a headache and lose its shape over time. If you're in doubt, size up.
How to Measure Your Head for a Hat
If you get the measurement wrong, the calculator won't help you much. You need to be precise. Grab a soft measuring tape or even just a piece of string and a ruler.
Follow these three steps to get it right.
- Position the tape: Wrap the tape around your head. It should sit about half an inch above your ears and eyebrows. This is the exact spot where a hat normally rests.
- Keep it level: Make sure the tape is level all the way around. If it's dipping down at the back or pulled too high at the front, your size will be wrong. It should be parallel to the ground all the way around.
- Don't pull too tight: The tape should be snug but not digging into your skin. You're looking for a comfortable fit, not a tight one.
Pro Tip: Our best advice is to measure twice. If you get the same number both times, you know you're good to go.
For the best result, you need an exact measurement. If you're using a string or just want to make sure you're avoiding common mistakes, follow our detailed guide on how to measure your head properly to get a pro-level fit.
What Size Is a 22.5 Inch head?
If your head measures exactly 22.5 inches, you might notice it does not fit perfectly into one category on most charts.
In the US system, 22.5 inches sits right between a size 7 1/8 and a 7 1/4. In the metric system, this is roughly 57.2 centimeters.
Our advice is to always get a hat slightly bigger by choosing a size 7 1/4 or 58cm. It is much easier to make a slightly loose hat fit better by adding a small hat liner.
But if you buy a hat that is too small, it will be uncomfortable and can even cause headaches. If you are stuck at 22.5 inches, always size up for a better fit.
Skip the charts next time
Got your size? Great.
Save or bookmark this hat size calculator now so you don't have to hunt for these charts again.
Since you've got your measurement, you might as well choose a hat that actually suits your face shape so you don't end up returning it later.
FAQs About Hat Sizes
How do I pick the right hat size?
The best way to pick your size is to measure your head circumference in centimeters. Once you have that number, check it against the brand's specific size chart. If you're between two sizes, always go with the larger one for a more comfortable fit.
Is a 7 1/4 hat medium or large?
A 7 1/4 hat is generally considered a Large. In the metric system, this is 58 centimeters. While some brands might categorize it differently, most standard charts place 7 1/4 at the beginning of the large range.
How big is a 7 7/8 hat?
A 7 7/8 hat is a very large size, measuring exactly 24 5/8 inches or 63 centimeters. This is usually labeled as an XXL or even 3XL, depending on the brand.
What is the average head size for men?
The average head size for an adult male is about 22 1/2 inches (57 cm), which translates to a US hat size of 7 1/4. However, anything between 7 1/8 and 7 1/2 is considered very common for men.
What if my head size is exactly 22 inches?
A 22-inch head matches a US size 7 or 56 cm. This is a very common size, but since it sits on the edge of "Medium," always check if the hat material is prone to shrinking (like 100% cotton).
Is 7 1/2 considered a large head size?
A 7 1/2 is slightly above average, but it is not "huge." Most adult men fall between 7 1/8 and 7 1/2. If you wear this size, you will usually fit into an XL in international sizing.
Is it better to buy a hat that is too big or too small?
Always go slightly bigger. You can easily fix a loose hat with foam or a small piece of fabric inside the sweatband, but a tiny hat will just give you a headache. It's better to know how to pick hats for larger heads, so you don't have to deal with that tight, annoying fit.
How accurate are these measurements?
If you use a soft measuring tape and keep it level, the measurement is very reliable. However, keep in mind that handmade hats (like some straw fedoras) can vary by 1-2 millimeters. Measuring twice is the best way to be sure.